The Peter Attia Drive - #289 - AMA #56: Cancer screening: pros and cons, screening options, interpreting results, and more

Episode Date: February 12, 2024

View the Show Notes Page for This Episode Become a Member to Receive Exclusive Content Sign Up to Receive Peter’s Weekly Newsletter In this “Ask Me Anything” (AMA) episode, the conversation focuses on cancer screening, a topic often shrouded in confusion yet crucial to understand given that early identification of a cancer is an essential part of survival strategy. Peter examines the arguments both for and against cancer screening, including addressing why some trials may show no benefit to screening. He then delves into the various screening modalities available for different cancers, highlights the pros and cons associated with each, and explains how to interpret the results. Additionally, Peter provides guidance for navigating outside of the relatively narrow and confined screening guidelines for various types of screening tests. If you’re not a subscriber and are listening on a podcast player, you’ll only be able to hear a preview of the AMA. If you’re a subscriber, you can now listen to this full episode on your private RSS feed or our website at the AMA #56 show notes page. If you are not a subscriber, you can learn more about the subscriber benefits here. We discuss: Why understanding cancer screening is crucial [2:45]; The prevalence of cancer diagnosis and mortality rates [4:30]; Why cancer screening and early detection is such an important part of the strategy to survive a cancer diagnosis [11:00]; Data on how cancer screening impacts survivability of cancer [16:30]; Inconsistencies between cancer screening trials regarding benefits to survival rates [25:45]; What are some of the reasons why clinical trials don’t always improve cancer-specific mortality? [30:15]; What are the arguments against population-level cancer screening? [42:00]; Cancer screening outside the recommended guidelines: risks and benefits, interpreting results, and other considerations [46:00]; Understanding sensitivity and specificity when reviewing screening results [52:30]; Risks and complications associated with colonoscopies [55:45]; Cancer screening modalities: options for cancer screening both within standard recommendations and beyond [58:30]; The strengths and limitations of various types of cancer screening [1:02:15]; Understanding positive and negative predictive value using sensitivity, specificity, and pretest probability [1:11:45]; Factors that influence an individual's pretest probability of cancer [1:13:45]; How to interpret cancer screening results [1:18:15]; The importance of having an advocate when considering out-of-guideline cancer screening tests [1:23:30]; How stacking multiple cancer screening modalities can decrease the risk of false positives [1:29:30]; Advice and guidance for making decisions related to cancer screening [1:31:15]; and More. Connect With Peter on Twitter, Instagram, Facebook and YouTube

Hey everyone, welcome to a sneak peek Ask Me Anything or AMA episode of the Drive podcast. I'm your host Peter Atia. At the end of this short episode, I'll explain how you can access the AMA episodes in full, along with a ton of other membership benefits we've created. Or you can learn more now by going to peteratea.md.com forward slash subscribe. So without further delay, here's today's sneak peek of the Ask Me Anything episode. Welcome to Ask Me Anything episode 56. I'm once again joined by my co-host, Nick Stenson. In today's episode, we focus the entire episode on cancer screening.

Cancer is what I refer to as one of the four horsemen of death, and it's certainly a killer that we've all been affected by in some way or another. It's a topic that has a lot of confusion around it, that is the screening part of it, and it's one that we see a lot of questions come up. In today's AMA, we gathered those questions, and we cover the following. The arguments for and against cancer screening, and why some trials may show no benefit to

cancer screening. The various modalities that are available to people to screen for different cancers, and the pros and cons of each of these. And then we discuss what people should know and how they should think about undergoing cancer screening individually. In other words, all of these data focus on the population. But the question is, how do you take those population data and bring them to your own life as you make decisions?

We talk about how you should interpret results, and we talk about how people should think about this if they plan to go outside of the relatively narrow and confined screening guidelines and pay out of pocket for various types of screening tests. I think this is an especially important topic because unlike the other horsemen, cardiovascular disease, neurodegenerative disease, and metabolic disease, cancer is the one for which we have the least insight into how to prevent the disease. We know the obvious environmental triggers such as smoking and poor metabolic health, but the reality of it is many cases of cancer arise for purely bad luck. In other

words, there are many people who are doing everything right and they still get cancer. And as such, early identification of cancer is an essential part of cancer strategy. The reason for that is simple. The lower the burden of tumor, the greater the outcomes in cancer therapy. If you're a subscriber and you want to watch the full video of this podcast, you can find it on the show notes page. If you're not a subscriber, you can watch a sneak peek of this video on our YouTube page. So without further delay, I hope you enjoy AMA number 56.

Peter, welcome to another AMA. How are you doing? Number 56. Peter, welcome to another AMA. How are you doing? Very well. How are you? I'm doing good. Any stories you'd like to share before this AMA starts? I asked this question with nothing in particular in mind.

I'm just curious if anything jumps out to you. Yeah, okay. That's funny you say that because I was worried that there was something that I didn't know that I was supposed to be aware of, but no, there are no stories to share. Okay, alright. With that, we'll get rolling. So, today's AMA is going to focus all around one topic, and it's a topic we see questions come through weekly. And it seems like there's a lot of confusion around this topic, and that topic is cancer screening. And ultimately we see questions around how should I think about cancer screening? Is it important?

Is it beneficial? There'll be sometimes articles in the news talking about how cancer screening is beneficial. Others talking about how studies came out in cancer screening is not beneficial. And so I think it just creates a lot of confusion for people around this topic. And so what we decided to do is just gather all these questions for today's AMA and just kind of go through cancer screening in general. This will be the cases for and against cancer screening, why some trials may show benefit while others don't, what modalities do people have and what are the different options for cancer screening, including the pros and cons of each of them and then also what should people think

about when they get cancer screen whether it's within traditional guidelines or what we're seeing more so now is if people are paying out of pocket outside of traditional guidelines and so I think it will be really good. I think at times it can get a teeny bit technical, but I also think that's the price you have to pay to really understand how to think about this. So all that said, anything you wanna add before we get started with the first question?

No. I think it'll be really helpful to set the stage for people understanding how common is a cancer diagnosis and then from there, how common is it for someone who gets diagnosis to die from cancer. I think that would be helpful for people to understand why it's worth putting the time and effort into understanding this topic at a deeper level. I remember when I was training, you always wanted to keep things sort of simple. So the really simple heuristic that we used to keep in mind, which you'll see in a moment when I provide more detail, is actually not perfectly correct, but is reasonable, is that

a person in the US has a lifetime incidence of cancer about one in three, and about half the time it's going to be fatal. So one in three chance of getting cancer in your lifetime, one in six chance of dying. Now it turns out that that's an underestimate. So what are the most recent numbers? Most recent numbers are that men have a lifetime incidence of just under 41% and indeed about half of those are fatal.

So 20.2% lifetime risk of dying from cancer. 20.2% lifetime risk of dying from cancer. For women, the numbers are slightly better, 39.1% lifetime risk of cancer diagnosis with just under half of those being fatal, 17.7%. So again, the adage that it was 1 3rd, 1 6th, you could see is an underestimate there. I think a more relevant way to look at this though is not just to look at it through that lens, which by the way, people have probably heard me say many times and I certainly talk

about it in the book. Cancer is the second leading cause of death in the United States and globally second, of course, only to ASCVD. But I think it's probably more maybe insightful to compare this through decades of life. And rather than just have me rattle these off, let's pull up the first table, Nick. I will of course rattle these numbers off because I know that there are people who are only listening to us, but this certainly sets the stage. The way this table is organized, of course, is by decade.

So we're looking at people aged 25 to 34, 35 to 44, etc., all the way up to 85 and plus. And we're looking at kind of three things. So the first is, what percentage of deaths in that decade are attributed to cancer? Then we're looking at the actual rate of cancer death. And this is always done in deaths per 100,000. So what is the number of deaths per 100,000? And what is the rank of cancer relative to other types of death within that decade? And for the cases where cancer is not number one, what is number one? With that said, let's start at the lowest end of the spectrum. This is lowest in terms of lowest mortality because the number you really want to anchor to is what's the absolute death rate?

And that's going to be in how many cases per hundred thousand so in that first decade we compare in the ages of 25 to 34 Cancer accounts for eight deaths per hundred thousand individuals not many people fortunately are dying that young It represents six percent of total deaths ranking third. So there are two things that rank significantly higher. And not surprisingly, the number one cause of death in that demographic is accidental death. And of course we've talked about this before, accidental death, the number one cause of that

is hands down overdose death. Okay, so you go up to the next category, 35 to 44, the percent of deaths attributed to cancer goes up from 6 to 13 percent, and the rate of death goes up threefold, goes to 26 deaths per hundred thousand. It is still the third leading cause of death, trailing accidental death, again the leading cause of death, And again, tragically that turns out to be overdoses as well. So we go into the next decade. This is where I sit plumply, 45 to 54. Here cancer now accounts for 23%

of all deaths in someone my age. The rate of cancer deaths again jumps sharply from 26 to now 88 per hundred thousand and it technically ranks second although I put a little asterisk here because here is where cancer and a SCVD are constantly switching with each other. So I would say it kind of ranks first or second here and it's either a SCVD or cancer that are in the number one spot. And then accidents tends to fall to number three here. So you go one decade up, 55 to 64. The percentage of deaths attributed to cancer

is now almost a third. It's 30% of deaths. And by the way, this is almost the maximum share of cancer deaths you'll see. It now rises to the number one cause of death in that age group, and it now accounts for 267 deaths per 100,000. This is a very big number. Go up another decade, and it basically is the same story. It's 31% of deaths attributed. It is the leading cause of death, and it now

has doubled to 553 deaths per 100,000. Now you've made it to the age of 75, what happens? Well, it turns out that other diseases are kind of exploding and so cancer now falls to second. Again, ASCVD takes over, but cancer still accounts for a quarter of deaths, but the absolute rate continues to rise. It doubles again to 1,036 deaths per 100,000 people. Again, ASCVD is number one, and when you go out, past 85, ASCVD holds on to its number one spot, and cancer takes the number three spot. It tends to fall, although its absolute numbers go up. 1649 deaths per 100,000 falls to 12% share.

So here a neurodegenerative disease tends to come up and take that place of cancer. So again, why do I go through all of those stats? Well, I think the point I'm trying to make here is there's really no decade of life in which cancer is not at least top three causes of death. And by extension then, I guess anybody listening to this is probably thinking of cancer. The other thing I would say is it would be impossible to listen to this and not know someone who has either battled cancer or

who has outright died of cancer. Yeah, Peter, I think that's really good for people to kind of see decade by decade just how prevalent it is and start to see how once you hit that 45 plus range, it starts to become much more relevant, which is a vast majority of people listening to this. So I think the next question then is, how does cancer screening fit into this? So why is cancer screening something important for people to think about if hearing that their goal is to not die early from cancer. I think we want to sort of take a step back and compare, again, cancer to ASCVD. It shouldn't be lost to anybody that ASCVD is the leading cause of death at this point,

but we understand what drives ASCVD so well. We really understand the relationship between lipo proteins, hypertension, smoking, and metabolic health. And those are basically the big four drivers of ASCVD. There are certainly genetic things in there that one has to pay attention to such as LP-little-A, familial hypercholesterolemia, and things like that. But again, those tend to be relegated down into issues that can be managed pharmacologically. And so in other words, we have a clear understanding of how that disease progresses, and we can monitor a person's progress towards that disease. We have the biomarkers that predict

risk. Furthermore, we have tools like CT angiograms that allow us to at least somewhat grossly look at the anatomy of the coronary arteries and get a sense of how advanced disease might be. When it comes to cancer, none of that's really true. Outside of smoking, and as we'll talk about certain genetic conditions, poor metabolic health, it's still a little bit of a black box as to why people get cancer. And more importantly, what one can do to reduce risk. So we've talked at length about the things that one can do to reduce risk, and we won't rehash that here. What we have to acknowledge is that we have two things

working against us in the cancer equation that we have working for us in the heart disease equation. So one is just that, right? We have a far less command over the biology of the disease. Secondly, we have far fewer effective treatments for the disease once it is advanced. So I think the easiest way to understand that is to look at both five and 10 year survival curves. So we pulled these up for just a couple of the most common cancers out there.

In fact, these are the five leading causes of cancer death, only in alphabetical order. The rank, of course, goes lung first, and pancreatic would be the lowest in the top five. But the point I want to make here is when you look at five-year survival, you look at this in two stages. You look at what we consider early stage one, stage two. So this is regional cancer, local cancer actually hasn't even spread to a lymph node. You look at stage three, which is the cancer has spread to a lymph node, but no further. And you look at stage four, which is to say,

this cancer has now left the lymph node and gone to a distant site. So you can see that in breast cancer, by the way, we always think about this in two forms. We think about her two new positive and negative, estrogen receptor positive and negative and triple negative. And if anybody needs a refresher on that, we have a great podcast we did on breast cancer that explains why these are three basically very different

diseases. But you can see the difference in survival between all of these cancers at an early stage where it ranges from 92 to 100% stage 1 to survival. To stage 4 where you have metastatic disease, it's 13 to 40%. So significant difference. And by the way, those are much better numbers than they used to be. Breast cancer is probably one of the bigger success stories of the past 20 years in terms of stretching out median survival. When you look at colorectal cancer, if it's a colorectal cancer that is caught before it's gone to the lymph nodes, we're talking about 88% for five years' survival. But if it's gone to lymph nodes, that goes down to 70%, and if it's spread to the liver,

it's down to 16%. Lung cancer ranges from 59% early to 6% late. Prostate is 100% early, 33% if it spreads. And of course the worst of all of these is pancreatic. If you can at least catch it in stage one, stage two, it's 38% five-year survival versus 3% if it's distant. I won't go through the same analysis for 10-year survival for the sake of time, but will include

the table so that people can see. The only thing I'd point out is, of course, the trends are even more dramatic when you start to go to 10-year survival. In other words, the difference between stage one and stage two survival versus stage four survival at 10 years is even a bigger chasm. So why do I bring this all up? Well, I bring this up to say that despite all of the advances we've had in the past 20 years and clearly hormone therapy

for breast cancer and immunotherapy for a number of other cancers, particularly checkpoint inhibitors, still leave us with a lot to be desired, especially when it comes to late stage cancer. I think that just leaves anyone who thinks about this realizing if you're going to get cancer, you certainly do not want to be in the position where that diagnosis is being made once the cancer is advanced, once the cancer has had a chance to spread. You really want to be able to diagnose cancer and manage it when it's in the stage one, stage two phase. Peter, I think that leads to one of the questions that we get asked about by far the most,

which is people reading stories, reading studies, and really wondering, do clinical trials on cancer screening show any benefits in reducing cancer deaths. This is really the crux of what we're here to talk about today because this has become a controversial topic. Thank you for listening to today's sneak peek AMA episode of The Drive. If you're interested in hearing the complete version of this AMA, you'll want to become a premium member. It's extremely important to me to provide all of this content without relying on paid ads. To do this, our work is made entirely possible by our members.

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